So I recently built a new system and it's worked fine for a few weeks, but now I'm getting some crazy instability and I don't know what the cause is. The computer just randomly restarts, no BSOD - although I once had a BSOD stating "video_tdr_failure".
I looked at the Windows event logs and nothing, just an error stating an unexpected restart occured. Every time I run Furmark, OCCT, MemTest, etc., temps are normal, no reboot. But sometimes it'll occur when I'm browsing the web, or writing in Visual Studio, or playing a game, there doesn't seem to be any connection between what I'm doing and those restarts. It even restarted once when it was doing nothing, I was away and my account locked.
When it restarts, the screen goes black, sound continues playing for a few seconds. Also often these happen several times in a row, i.e. when it has restarted there's a high chance it'll restart again right after I get into Windows again.
I've updated all drivers to the latest as well as the BIOS. I loaded the optimized defaults to make sure my overclock wasn't the cause. This did nothing, and I was kind of expecting this because the computer was running fine before with these drivers.
The only things I've changed recently were the PSU - I've switched to an XFX Pro 750W Black Edition because my Cooler Master 620W Silent Pro M2 had its fan spinning 100% all the time, and replaced the power strip which had started buzzing. I'm not excluding the PSU but at the same time, I can load the system 100% (OCCT Linpack + Furmark) and it doesn't cause reboots.
Gonna try running MemTest all day tomorrow, for what it'll be worth.
2x Kingston DDR3 1600mhz 8GB
Samsung 840 Pro 256GB SSD
Western Digital Red 2TB Hard drive
2x GTX 760s in SLI
XFX Pro 750W Black Edition
Fractal Design Define R4
Monitor: BenQ XL2720T 120hz